Lifting mechanism for desk

Abstract

A lifting mechanism for desk including a first bracket, a second bracket, and at least one lever assembly is provided. The first bracket includes a first plane. The second bracket includes a second plane. The lever assembly is connected between the first bracket and the second bracket so that the first bracket moves close to or moves away from the second bracket through the lever assembly, and the first plane is tilted relative to the second plane when the first bracket is away from the second bracket. The lever assembly includes at least two levers, and lengths of the at least two levers are different.

What is claimed is: 
     
         1 . A lifting mechanism for desk, comprising:
 a first bracket, comprising a first plane;   a second bracket, comprising a second plane; and   at least one lever assembly, connected between the first bracket and the second bracket so that the first bracket moves close to or moves away from the second bracket through the at least one lever assembly,   wherein the first plane is tilted relative to the second plane when the first bracket moves away from the second bracket, and the at least one lever assembly comprises at least two levers, and lengths of the at least two levers are different.   
     
     
         2 . The lifting mechanism for desk as claimed in  claim 1 , wherein a tilt angle between the first plane and the second plane increases as a distance between the first bracket and the second bracket increases when the first bracket moves away from the second bracket. 
     
     
         3 . The lifting mechanism for desk as claimed in  claim 1 , wherein the first plane is parallel to or is tilted relative to the second plane when the first bracket moves close to and overlaps the second bracket. 
     
     
         4 . The lifting mechanism for desk as claimed in  claim 1 , further comprising:
 a torsion spring, disposed at a position where the at least one lever assembly is pivoted to the first bracket or the second bracket, wherein the torsion spring is abutted between the at least one lever assembly and the first bracket or the second bracket so as to drive the at least one lever assembly to rotate with respect to the first bracket or drive the at least one lever assembly to rotate with respect to the second bracket.   
     
     
         5 . The lifting mechanism for desk as claimed in  claim 1 , wherein the at least one lever assembly comprises:
 a first lever, one end of the first lever being pivoted to one of the first bracket and the second bracket, the other end of the first lever being movably disposed at the other one of the first bracket and the second bracket through a first rail assembly; and   a second lever, one end of the second lever being pivoted to one of the first bracket and the second bracket, the other end of the second lever being moveably disposed at the other one of the first bracket and the second bracket through a second rail assembly.   
     
     
         6 . The lifting mechanism for desk as claimed in  claim 5 , wherein the first rail assembly comprises a first rail and a first sliding member, the first sliding member is slidably coupled to the first rail, the first rail is disposed at the first bracket or the second bracket, and one end of the first lever is pivoted to the first sliding member, wherein the second rail assembly comprises a second rail and a second sliding member, the second sliding member is slidably coupled to the second rail, the second rail is disposed at the second bracket or the first bracket, and one end of the second lever is pivoted to the second sliding member. 
     
     
         7 . The lifting mechanism for desk as claimed in  claim 6 , wherein the first sliding member or the second sliding member has an engaging flange, and the lifting mechanism for desk further comprising:
 a positioning member, comprising a pivoting end, a forcing end, and a plurality of positioning slots located between the pivoting end and the forcing end, the pivoting end being pivoted to the first bracket or the second bracket such that the positioning slots are located next to a sliding path of the first sliding member or a sliding path of the second sliding member; and   a stirring member, pivoted to the first bracket or the second bracket, the stirring member comprising a protruding rod movably extending to the forcing end, the stirring member being adaptable to be driven by an external force so that the protruding rod pushes the forcing end, such that the positioning member rotates with respect to the first bracket or the second bracket and enables the engaging flange to be engaged in one of the positioning slots.   
     
     
         8 . The lifting mechanism for desk as claimed in  claim 7 , further comprising:
 an elastic member, abutted between the first bracket and the positioning member or abutted between the second bracket and the positioning member, the elastic member constantly driving the positioning member and the engaging flange to be engaged with each other, or the elastic member constantly driving the positioning member and the engaging flange to be away from each other.   
     
     
         9 . The lifting mechanism for desk as claimed in  claim 5 , further comprising:
 a pivoting member, pivoted between the first lever and the second lever, the first lever crossing the second lever.   
     
     
         10 . The lifting mechanism for desk as claimed in  claim 5 , further comprising a user side and a back side, wherein a length of the first lever is less than a length of the second lever, the first bracket moves towards the user side away from the back side when the first bracket moves away from the second bracket, and a position where the first lever is pivoted to the first bracket and a position where the second lever is pivoted to the second bracket are both located at the user side. 
     
     
         11 . The lifting mechanism for desk as claimed in  claim 5 , wherein the first lever is parallel to the second lever, the first lever and the second lever are pivoted to the second bracket and are slidably disposed at the first bracket, and the at least one lever assembly further comprises:
 a third lever, one end of the third lever being pivoted to the first bracket, the other end of the third lever being pivoted to the first lever.   
     
     
         12 . The lifting mechanism for desk as claimed in  claim 11 , wherein a length of the third lever is less than a length of the first lever, and the length of the first lever is less than a length of the second lever. 
     
     
         13 . The lifting mechanism for desk as claimed in  claim 12 , further comprising a user side and a back side, wherein the first bracket moves towards the user side away from the back side when the first bracket moves away from the second bracket, and a position where the first lever is pivoted to the second bracket and a position where the third lever is pivoted to the first bracket are both located at the user side. 
     
     
         14 . The lifting mechanism for desk as claimed in  claim 1 , wherein the at least one lever assembly comprises:
 a first lever, two opposite ends of the first lever being respectively pivoted to the first bracket and the second bracket; and   a second lever, two opposite ends of the second lever being respectively pivoted to the second bracket and the first bracket.   
     
     
         15 . The lifting mechanism for desk as claimed in  claim 14 , wherein a length of the first lever is less than a length of the second lever, the first lever is parallel to the second lever, the lifting mechanism for desk further comprises a user side and a back side, the first bracket moves towards the user side away from the back side when the first bracket moves away from the second bracket, and the first bracket and the second bracket are not aligned with each other, wherein a position where the first lever is pivoted to the second bracket is located at the user side, and a position where the second lever is pivoted to the first bracket is located at the back side.